首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1362篇
  免费   53篇
  国内免费   14篇
耳鼻咽喉   4篇
儿科学   43篇
妇产科学   21篇
基础医学   207篇
口腔科学   34篇
临床医学   101篇
内科学   229篇
皮肤病学   10篇
神经病学   100篇
特种医学   172篇
外科学   206篇
综合类   14篇
一般理论   1篇
预防医学   70篇
眼科学   11篇
药学   114篇
中国医学   5篇
肿瘤学   87篇
  2023年   7篇
  2022年   33篇
  2021年   33篇
  2020年   18篇
  2019年   26篇
  2018年   26篇
  2017年   24篇
  2016年   25篇
  2015年   30篇
  2014年   41篇
  2013年   70篇
  2012年   126篇
  2011年   159篇
  2010年   51篇
  2009年   43篇
  2008年   93篇
  2007年   125篇
  2006年   85篇
  2005年   78篇
  2004年   70篇
  2003年   67篇
  2002年   44篇
  2001年   14篇
  2000年   10篇
  1999年   10篇
  1998年   19篇
  1997年   8篇
  1996年   5篇
  1995年   7篇
  1994年   8篇
  1993年   7篇
  1992年   11篇
  1991年   9篇
  1990年   5篇
  1988年   4篇
  1987年   4篇
  1986年   3篇
  1985年   3篇
  1983年   3篇
  1982年   1篇
  1981年   1篇
  1979年   3篇
  1978年   2篇
  1977年   3篇
  1976年   4篇
  1973年   3篇
  1971年   3篇
  1969年   2篇
  1968年   1篇
  1967年   1篇
排序方式: 共有1429条查询结果,搜索用时 15 毫秒
81.

Background  

Although there has been continuous evolution in the management of fracture fixation, treatment for osteoporotic proximal humerus fractures is still challenging to trauma surgeons. The purpose of this study was to report early failure of the locking compression plate (LCP) in the treatment of osteoporotic proximal humerus fracture and characterize the mode of failure.  相似文献   
82.
BACKGROUND: The aim of this study was to examine prothrombogenic factors and antioxidative defense in obese children and adolescents with pre-metabolic and metabolic syndrome, and to analyze insulin secretion and resistance, early glycoregulation disorders and lipid status. METHODS: Insulin sensitivity was determined using the homeostasis model assessment for insulin resistance (HOMA-IR), while insulin secretion was determined using the homeostasis model assessment beta (HOMA-beta). Prothrombogenic factors analyzed were plasma plasminogen activator inhibitor-1 (PAI-1) and fibrinogen. Superoxide dismutase and glutathione peroxidase were measured as markers of antioxidative defense. RESULTS: Patients with metabolic syndrome were characterized with increased body mass index (BMI), waist circumference, and HOMA-IR and HOMA-beta levels, and all had increased blood pressure and triglyceride levels, low high-density lipoprotein cholesterol levels, increased PAI-1 levels and reduced antioxidative defense levels. Patients with pre-metabolic syndrome had higher levels of basal and mean insulinemia during an oral glucose tolerance test, higher levels of HOMA-beta and lower levels of antioxidative defense compared to patients with metabolic syndrome. CONCLUSIONS: Negative correlations between antioxidative defense parameters and BMI, abdominal obesity, insulin secretion, systolic blood pressure and atherogenic lipid factors, as well as correlations between PAI-1 and insulin resistance and basal glycemia in the metabolic syndrome group contribute to accelerated atherosclerosis. Positive correlations between PAI-1 and waist circumference and BMI, and negative correlations between BMI and antioxidative defense in the pre-metabolic syndrome patients show that this early stage preceding the metabolic syndrome is also characterized by atherosclerotic complication risks and evident hyperinsulinism and insulin resistance.  相似文献   
83.
BACKGROUND: The role of AT2R in regulation of blood pressure (BP) was mainly investigated in animal models. It is proposed to be a negative regulator of BP. X-linked AT2R -1332 A/G polymorphism has been denoted as functional. This polymorphism was associated with certain cardiovascular phenotypes in hypertensive patients, but it was poorly investigated in essential hypertension. The aim of our study was to evaluate possible association of -1332 A/G gene polymorphism with essential hypertension in males from Serbian population. METHODS: The study group included 304 men of Caucasian origin, 190 normotensive (NT) and 114 hypertensive (HT), free of cardiovascular disorders. Genotyping was done by PCR RFLP method. RESULTS: G/- genotype was in association with HT (OR 1.6, CI=1.0-2.6, p=0.04). Stratification by age (<40 years, mean 31.65+/-5.29 and >40 years, mean 51.36+/-8.32) pronounced significance only in older males (OR 2.4, CI=1.2-5.0, p=0.02). After adjustment for confounding factors the OR for hypertension remained unchanged and significant (adjusted OR 2.3, CI=1.0-5.4, p=0.04). Conclusion: Hemizygosity for the G allele was found to be susceptibility factor for hypertension in males. Still, clarifying the role of AT2R in development of human hypertension requires further replication studies in larger and different populations.  相似文献   
84.
Brain Topography - Stress may impact the ability to effectively regulate emotions. To study the impact of stressful experiences in early and recent life on emotion regulation, we examined the...  相似文献   
85.
86.
The incidence of hypertension is increasing and it is more common in man than in women. Up to date, MMP-3 5A/6A polymorphism has been associated with artery stiffening and elevated blood pressure, whereas results considering association of endothelial NOS (eNOS) G894 T polymorphism with hypertension are controversial. The aim of our study was to analyze the possible association of eNOS G894 T and MMP-3 5A/6A gene polymorphisms with hypertension in Serbian population. Study sample consisted of 172 hypertensive and 200 normotensive subjects divided by gender. Both female and male group was truncated according to age. All subjects were genotyped for MMP-3 5A/6A and eNOS G894 T polymorphism. There was a significantly higher (P < 0.05) prevalence of 5A/5A genotype in hypertensive females compared to normotensive ones (19.30 % vs. 10.84%) even more pronounced in group > or =50 years, according to its recessive effect. In young males (<40 years), we found 3.7-fold increased risk for hypertension associated with allele 6A (P < 0.01), and 8.1-fold with genotype 6A/6A (P = 0.01) according to recessive model. We found no association of eNOS G894 T polymorphism with hypertension. These results indicate that there were gender- and age-specific differences in association of MMP-3 5A/6A polymorphism with hypertension in Serbian population.  相似文献   
87.
We describe double rocket immunoelectrophoresis for simultaneous quantification of apolipoprotein A-I (apo A-I) and B (apo B) in blood on filter paper. The apolipoproteins from blood spots on filter paper were eluted with detergents (sodium dodecyl sulfate and Triton X-100). The eluates were subjected to electrophoresis on agarose gel containing antisera against both apolipoproteins. Within- and between-assay CVs for apo B/A-I ratios were less than 5.5% and 7.2%, respectively. The apo B/A-I ratio was influenced by length and temperature of storage. In results for 121 venous blood samples, the apo B/A-I ratios in dried blood spots correlated well with those in serum (r = 0.92) and correlated somewhat with the ratios for low-density lipoprotein/high-density lipoprotein cholesterol in serum (r = 0.87). Of these specimens, 68 were from patients with known familial hypercholesterolemia, all of whom had an apo B/A-I ratio greater than 0.90. We think this method will be of value for detecting familial hypercholesterolemia and possibly familial hyperapobeta- and hypoalphalipoproteinemia.  相似文献   
88.
In recent years there has been growing interest in blood conservation and avoidance of transfusion in patients undergoing orthopedic surgery. The benefits of blood transfusion must be considered and evaluated in terms of risk factors relating to the adverse effects of transfusion. A number of strategies are available to reduce the need for blood transfusion. These strategies are maximally effective if combined to span the pre-operative, intra-operative and post-operative periods. Surgical, anesthetic and pharmacological techniques can reduce blood loss during operation and the use of allogenic blood. This article presents current opinions, on the base of contemporary literature, regarding risks of transfusion and several simple techniques that will reduce the need for transfusion in orthopedic procedures.  相似文献   
89.
90.
The European Network of Forensic Science Institutes (ENFSI) recommended the establishment of forensic DNA databases and specific implementation and management legislations for all EU/ENFSI members. Therefore, forensic institutions from Bosnia and Herzegovina, Serbia, Montenegro, and Macedonia launched a wide set of activities to support these recommendations. To assess the current state, a regional expert team completed detailed screening and investigation of the existing forensic DNA data repositories and associated legislation in these countries. The scope also included relevant concurrent projects and a wide spectrum of different activities in relation to forensics DNA use. The state of forensic DNA analysis was also determined in the neighboring Slovenia and Croatia, which already have functional national DNA databases. There is a need for a 'regional supplement' to the current documentation and standards pertaining to forensic application of DNA databases, which should include regional-specific preliminary aims and recommendations.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号